The present invention relates to regulated voltage supply circuits and, more particularly, to regulated voltage supply circuits with protection against the effects of voltage magnitude surges.
Modern aircraft have many electrical and electronic devices positioned and operating therein. All such devices, unless batteries or generators, require electrical power to be supplied thereto to operate, and usually also require, in at least some portions thereof, that this power be regulated in some sense. Typically, a voltage from a voltage source is supplied to such devices with the magnitude thereof regulated to some extent so as to generally remain at or near some selected value. Often, the supply electrical conductors over which such regulated voltage is supplied from the source to the devices extend for substantial distances through the aircraft and are connected to plural ones of such devices.
In operation, such aircraft will on occasion have to fly through or near thunderstorms and, as a result, will encounter lightening strikes thereon. Such strikes often cause short duration voltage magnitude surges on the supply electrical conductors, and such transient voltage excursions from the corresponding value selected therefor typically last somewhere around one to two hundred milliseconds and have peak magnitudes of several hundred Volts or more in waveform having a very rapid rise to such a voltage peak followed by a significantly slower falloff. Many of the devices supplied electrical power by the supply electrical conductors cannot withstand such surges without damage to at least some portions thereof, and so there is a desire to supply voltage of a selected value to such portions of these devices, or the entire device, in a manner protecting them, or it, from such surges.